In recent years, organic EL display devices, which use organic electroluminescence (EL) elements and are of the self-luminous type, have attracted attention as display devices that can replace liquid crystal display devices. For the organic EL display device, a seal structure is proposed to inhibit degradation of the organic EL element due to penetration of, for example, moisture and oxygen. The seal structure includes a sealing film covering the organic EL element, and the sealing film includes a stack of an inorganic film and an organic film.
For example, PTL 1 discloses an organic EL device in which an SiNx film is layered on the surface of an organic EL element through sputtering, after which an organic film is formed by applying a curable composition using an inkjet ejection apparatus and curing the composition. Finally, an SiNx film is layered through sputtering.